collision problem

[Janssen]

Im currently creating a snake game and am having issues collecting the eggs, with the code Im having trouble setting the range that the images top and left to collide with the eggs top and left range, they both strech from its initial top and left to top+120 and left+120

code:

If imgSnake(FrameCount).Left >= imgEgg.Left And imgSnake(FrameCount).Left + 120 <= imgEgg.Left + 120 Or imgSnake(FrameCount).Top >= imgEgg.Top And imgSnake(FrameCount).Top + 120 <= imgEgg.Top + 120 Then         SpawnEgg         Score = Score + 10     End If

[/list]

[wtd]

code:

imgSnake(FrameCount).Left >= imgEgg.Left And imgSnake(FrameCount).Left + 120 <= imgEgg.Left + 120 Or imgSnake(FrameCount).Top >= imgEgg.Top And imgSnake(FrameCount).Top + 120 <= imgEgg.Top + 120

This is just begging to be factored out into a boolean returning function that would take imgSnake and imgEgg as arguments.

Also, why is 120 significant? This is a "magic number," and it's a bad idea. Give it a name that tells people why it's important.

[Janssen]

Its the length of each side of both snake and egg images

[wtd]

Well then, let the code say that.

[Janssen]

I tried that and it doesnt seem to work, could u please show me more of a general line of code for collisions, i think that the problem is that it needs to hit the exact left and top coords instead of range.

[wtd]

Oh, I have no idea if your collision code works. I'm just trying to help you with more fundamental issues.

[cool dude]

do u have a grid where it perfectly alligns? because if u don't then u will end up eating half an egg. also if 120 is the length, its better to do:

code:

imgSnake(FrameCount).Left + imgSnake(FrameCount).width

This will make sure it takes the full length of the egg!

P.S. post your entire code b/c by the looks of it your if statement for collision is screwed up, and u aren't taking into account both sides. wat i mean by that is that to make sure the snake alligns u have to say if the snake hits the left side and the right side of the egg as well as the top then it eats it.

[Drewbie]

I think you r looking for sumthing like this

code:

If ((Image1.Left + Image1.Width) < Image4.Left + Image4.Width And (Image1.Left + Image1.Width > Image4.Left)) And (Image1.Top < (Image4.Top + Image4.Height) And Image1.Top > Image4.Top) Then          ElseIf (Image1.Left < Image4.Left + Image4.Width And (Image1.Left > Image4.Left)) And (Image1.Top + Image1.Height > Image4.Top And Image1.Top < Image4.Top + Image4.Height) Then         End If

where image1 is yur cnake and image4 is yur egg
u might be able to put it in on if statement but i dont no for sure
shud work

[Drewbie]

i have found an error in that code but corrected it

code:

If ((Image1.Left + Image1.Width) < Image4.Left + Image4.Width And (Image1.Left + Image1.Width > Image4.Left)) And (Image1.Top < (Image4.Top + Image4.Height) And Image1.Top > Image4.Top) Then ElseIf (Image1.Left < Image4.Left + Image4.Width And (Image1.Left + Image1.Width > Image4.Left)) And (Image1.Top + Image1.Height > Image4.Top And Image1.Top < Image4.Top + Image4.Height) Then End If

it wasnt registering the contact of the first images right side and bottom to the second images left side and top

[GlobeTrotter]

Here is your code, wrapped up into a private function:

code:

Private Function isCollision(ByVal img1 As Image, ByVal img2 As Image) As Boolean     isCollision = True Or _         ((img1.Left + img1.Width) < img2.Left + img2.Width And _         (img1.Left + img1.Width > img2.Left)) And _         (img1.Top < (img2.Top + img2.Height) And _         img1.Top > img2.Top) Or _         (img1.Left < img2.Left + img2.Width And _         (img1.Left + img1.Width > img2.Left)) And _         (img1.Top + img1.Height > img2.Top And _         img1.Top < img2.Top + img2.Height) End Function

Now you can just call it like so:

code:

if isCollision(Image1,Image4) then    '... end if